Blank-splitting device



Oct. 29, 1968 L. l. RITCHIE I 3,407,856

BLANK-SPLITTING DEVICE Filed Dec. 15, 1965 5 Sheets-Sheet 1 INVENTOR. LAO/D j. le/rcw/ A fi'OP/WF/ Oct. 29, 1968 L. I. RITCHQIE 3,

BLANK- SPLITTING DEVICE Filed Dec. 15. 1965 5 -She t 2 33 A l i4,

III I INVENTOR.

LZOVD Z. P/TcW/E 'AT'TORNE'Y Oct. 29, 1968 L. l. RITCHIE BLANK-SPLITTING DEVICE 5 Sheets-Sheet 5 Filed Dec. 15, 1965 m m E v N [AOYD 1. EITCH/E BY WM ATTORNE Y United States Patent Office 3,407,856 Patented Oct. 29, 1968 BLANK-SPLITTING DEVICE Lloyd I. Ritchie, Roosevelt Apartments, 4D, Chehalis St., Aberdeen, Wash. 98532 Filed Dec. 15, 1965, Ser. No. 513,968 4 Claims. (Cl. 144-193) ABSTRACT THE DISCLOSURE Two opposed resilient centering gripping means engage opposite sides of a generally fiat wood blank to be split by relative movement of such blank and a froe lengthwise of the grain of the blank. Each gripper means is resiliently deformable to engage irregularities in a principal surface of the blank. Such a gripper means may be composed of a row of resilient fingers supported in cantilever fashion or may be a pad of sponge plastic material. Such gripper means can be mounted for swinging movement about parallel axes between positions pressed against sides of a blank and positions spread apart to release the blank. Relative movement of a spliting froe and the blank can be effected by driving the froe by a fluid-actuated piston and cylinder, or the blank can be forced past a stationary froe by a plunger driven by a fluid-pressure piston and cylinder or by a link connected to an endless chain.

This invention is particularly applicable to apparatus for splitting blanks into boards in the process of manufacturing hand split, resawn shakes.

Blocks of red cedar or similar wood, usually of approximately quadrant shape and of a length equal to the length of shakes to be manufactured, are split by a froe into blanks having a thickness of 1% inches to 2 /2 inches and a width from a few inches up to 14 inches. Such a blank is of suflicient thickness to make the butts of two shakes and the tips of two shakes, and such thickness will be generally uniform from end-to-end of the blank. Such a blank is then split generally along a plane parallel to its two faces to make two boards of nearly equal thickness as possible. Each of these boards also should be of substantially uniform thickness throughout its length and of a thickness equal to the thickness of a shake butt plus the thickness of a shake tip, plus allowance for the thickness of a saw kerf. Such boards are then resawn on a diagonal to provide the butt of one shake at one end and the tip of such shake at the opposite end of the board, with the butt of a second shake at such opposite end of the board and the tip of such second shake at the first end of the board.

The purpose of the present invention is to provide apparatus which will facilitate splitting of shake blanks into boards, and which will enable such a blank-splitting operation to be performed more accurately.

A principal object of the invention is, therefore, to conserve timber from which shakes are manufactured and to increase the uniformity of handsplit shakes by effecting splitting of blanks into boards more nearly centrally between the opposite principal surfaces of the blank.

Another object of the invention is to provide apparatus for splitting shake blanks into boards automatically so that it is only necessary for an operator to supply blanks to the apparatus, actuate the apparatus to eifect the splitting operation and remove the resulting boards. Moreover, such apparatus may include mechanism to place individual blanks in position for splitting, in which case it is only necessary for an operator generally to supply blanks to the apparatus, and the apparatus can also remove the boards resulting from splitting of the blanks to a location remote from the splitting apparatus such as to the location of a resaw.

In such apparatus a specific object is to provide locating means which will locate a blank accurately in relation to a blank-splitting froe irrespective of the roughness of the opposite surfaces of the blank.

A further object of the invention is to provide apparatus which is semiautomatic in operation, yet which is economical to manufacture and will require a minimum of adjustment to handle blanks different length and thickness, and which will need a minimum of maintenance.

FIGURE 1 is a top perspective of a shake blank to be split and FIGURE 2 is a top perspective of one type of apparatus for splitting such blanks. FIGURE 3 is a detail section through centering mechanism of the apparatus.

FIGURE 4 is a side elevation of the blank-splitting device shown in FIGURE 2.

FIGURE 5 is a fragmentary side elevation of a modified blank-splitting construction.

FIGURE 6 is a plan of another type of blank-splitting apparatus; FIGURE 7 is a transverse section of such apparatus on line 7-7 of FIGURE 6, with parts broken away, and FIGURE 8 is a longitudinal section through such apparatus on line 8--8 of FIGURE 6.

FIGURE 9 is a longitudinal section through still a diiferent type of blank-splitting apparatus showing parts in one operative position, and FIGURE 10 is a similar view with parts in a different operative position.

FIGURE 11 is a detail top perspective of fingermounting mechanism with parts broken away.

FIGURE 12 is a longitudinal section of a portion of blank-splitting apparatus illustrating a modification of the apparatus shown in FIGURES 9 and 1f).

The blanks used in the manufacture of shakes for roof ing and sidewall construction, which are to be split by the apparatus of the present invention, are of a length corresponding to the length of the finished shake and may be from 16 inches to 30 inches, but usually would be 18 inches, 20 inches or 24 inches in length. The width of such a blank would vary within the range of 4 inches o 14 inches, but usually would be from 8 inches to 12 inches in width. The thickness of such a blank would be within the range of 1% inches to 2 /2 inches. A representative shake blank of the type to be split by the apparatus of the present invention is shown in FIGURE 1. It will be noted that the left end of this blank is quite flat because that was the location at which the froe entered the end of the block in splitting from it the blank illustrated. The opposite end of the blank, however, can have quite an irregular surface, as shown.

Blanks to be split by the apparatus of FIGURES 2, 3 and 4 are fed to the apparatus by a belt conveyor including a supporting frame 1, an endless belt 2 and rollers 3 mounted on the frame and disposed between the upper and lower stretches of the belt 2 for supporting it. On such belt are cleats 4 extending crosswise of the belt to engage the edges of blanks 5 for feeding them transversely of their lengths to the blank-splitting station. In splitting a blank into boards it is desirable for the froe to enter the end of the blank which has the most irregular side surfaces. Each of the resulting boards will then have one side with a fiat surface portion at one end and an irregular surface portion at the other end and the opposite side of such board will also have a flat end portion and an irregular end portion. Each end of each board will also have a fiat surface on one side and an irregular surface on its opposite side. Consequently, in resawing such a shake the planar cut will be from a location adjacent to the smoother side of one end of the shake to the smoother side of the opposite end of the shake so that the tip will be of substantially uniform thickness, whereas the butt will have one flat sawed side and the surface of the other side will be more or less irregular. This arrangement is desirable both to enhance the rustic appearance of the shakes and to provide a tip portion of substantially uniform taper over which the butt portion of an upper shake can lie smoothly.

For the reasons discussed above it is desirable to start the split of a blank from the end having the most runeven surface portions. In order to make the shakes produced from the resulting boards of substantially uniform butt thickness it is necessary for the froe to engage as near the center of the average block thickness as possible. For this purpose the location of the froe can be established more accurately by balancing gripping forces than simply by observation.

To position a shake blank by balancing gripping forces two opposed resilient centering gripper means, each resiliently deformable to engage irregularities in the surface of one side of the blank at the end to be engaged by the froe, are shown in FIGURES 2, 3 and 4 as including opposed rows of spring fingers. In FIGURES 2, 3 and 4 spring fingers 6 are mounted in one row by the bar 7 drilled at spaced intervals through which the supporting ends of the spring fingers can be inserted. This shaft is rotatively supported by one end in a post 8. The opposed row of spring fingers 9 beneath the spring fingers 6 is supported by a second rod 10, which also has one end rotatively mounted in the post 8.

To the supported end of the rod 7 is secured an arm 11 connected by a link 12 to an eccentric location of a disk crank 13 rotatively supported by a shaft 14 mounted in cantilever fashion on a support 15. Similarly, an arm 16 is mounted on and projects radially from the supported end of the rod 10. The swinging end of this arm is connected by a link 17 to an eccentric location on the crank disk 13 at the side of its axis opposite that to which the link 12 is connected. The disk crank is oscillated by a hydraulic jack 18 mounted between a pivot 19 on the support 15 and a pivot 20 connected to the lever arm 21 of the disk crank 13.

Hydraulic liquid is supplied to the connection 22 at one end of the jack 18, and to the connection 23 at the other end of such jack. Control over such liquid supply is effected by the operator swinging control lever 24. By swinging this lever in one direction liquid will be supplied to the connection .22 so that the jack will be contracted in effective length to the position shown in FIG- URE 4, in which the links 12 and 17 are projected away from each other to swing arms 11 and 16 into the psitions in which the gripping fingers 6 and 9 are in the solid-line positions shown in this figure in engagement with opposite sides of the blank. When the lever 24 is swung in the opposite direction hydraulic liquid will be supplied to the connection 23 and hydraulic liquid can return from the cylinder through the other connection 22. By this operation the jack 18 will be extended to rotate the crank disk counterclockwise for drawing the links 12 and 17 toward each other. Such movement of the links will swing the levers 11 and 16 toward each other also for rotating rods 7 and 10 to swing the resilient fingers 6 and 9 from the solid-line positions of FIGURE4 into the broken-line positions. In these positions the spring fingers will be withdrawn from contact with the blank.

The froe 25, for splitting the blank into boards 5a and 5b, is mounted on the end of a plunger 26 which is reciprocated by the fluid-pressure cylinder 27. Such cylinder is supported by an arm 28 from the post 8 in a position such that the froe 25 is centered between the rows of resilient fingers 6 and 9 when they are in their control the supply of the hydraulic liquid to these connections a lever 30 is provided for manipulation by the operator. When this lever is moved in one direction liquid will be supplied to the connection 29 for retracting the plunger 26. When the lever is swung to the other extreme position liquid under pressure will be supplied to the connection 29' at the other end of the cylinder 27 for projecting plunger 26 while liquid can be drained from the connection 29.

The width of belt conveyor 2 is small enough so that a substantial portion of the length of each blank projects beyond the conveyor belt, as shown in FIGURE 4. When the belt has been moved so that a cleat 4 locates a blank with its end in registry with the rows of resilient fingers 6 and 9, the belt will be stopped and the control lever 24- will be swung into a position such that jack 18 will be contracted to swing the rows of resilient fingers toward each other by rotation of the disk crank 13. These fingers will engage the projecting end of the blank, as shown in FIGURE 3, so that various fingers will engage portions of the blank surfaces at different elevations. The fingers will, however, cooperatively locate the blank so that its end adjacent to the froe will be lifted from the conveyor into a position centered with respect to the froe.

Next, the lever 30 can be swung by the operator for the purpose of supplying liquid under pressure to cylinder 27 so as to project the plunger 26 and drive the froe into the end of the blank 5. Such pressure will slide the blank endwise until its opposite end is engaged with the backing flange 31 on the side of the conveyor opposite the grippers and froe. The froe will then be moved from the position of FIGURE 2 to that of FIGURE 4, splitting the blank into the two boards 5a and 512. As the froe moves between the boards thus formed the boards will be spread apart, as shown in FIGURE 4, which will move apart correspondingly the resilient fingers 6 and 9. Such fingers will still hold the boards firmly in centered position with respect to the froe. The conveyor belt 2 is sloped sidewise sufficiently so that, as the froe pries apart the boards, the lower board 5b will be swung downward toward the conveyor belt without appreciable pressure being exerted on the conveyor belt, or upward on the froe.

When the blank 5 has been split into the boards 5a and 5b, as shown in FIGURE 4, the lever 24 is reversed so that the fingers 6 and 9 are swung into the broken line positions of FIGURE 4 to release the gripping pressure from the boards. The lever 30 can next be swung to its opposite position, which will cause the hydraulic cylinder 27 to retract plunger 26 and 25, leaving the boards in stacked relationship on the conveyor 2. Drive of the conveyor can then be resumed to shift the split boards out of registry with the gripper fingers 6 and 9 while the next blank to be split is moved by the conveyor into registry with the gripper fingers. The conveyor will then be stopped again and the splitting process will be repeated.

In FIGURE 5 blanksplitting apparatus, similar to that shown in FIGURES 2 and 4, is illustrated except that the blank-gripping means incorporates resilient pads 6' and 9' instead of thefingers 6 and 9, described above. Such pads may be soft sponge plastic or sponge rubber of considerable thickness so that their thickness can vary sufiici ently to embrace substantially contiguously the irregular surfaces of blanks such as shown in FIGURE 1. These pads 6' and 9 are mounted on the swinging ends of levers 11 and 16', respectively, which are mounted on fulcrum pivots in suitable upper and lower supports 8'.

On the ends of the levers 11 and 16 remote from the gripper pads 6' and 9 are rollers 12' and 17 which are engageable with the opposite lobes 13' of a cam rotatively mounted by a shaft 14'. The levers 11 and 16 are spring levers having the springs 11" and 16" engaged with their pivots, respectively, and with the levers to urge the padcarrying ends of the levers apart. Rotation of the cam to press its lobes 13 against the rollers 12' and 17' will swing such levers to move their pad-carrying ends toward each other in opposition to the force of the springs 11 and 16". When rotation of the cam is continued in the counterclockwise direction through a small angle the rollers will ride off the cam lobes so that the springs 11" and 16" can snap the pad-carrying ends of the levers into the broken-line positions illustrated.

The operation of the apparatus equipped with the levers 11' and 16' and the gripper pads 6' and 9' will be operated in substantially the same manner as described with reference to FIGURES 2 and 4. The shake blank 5 will be moved edgewise by the conveyor 2 until the end of the blank is in registry with the gripper pads 6" and 9. The cam will then be rotated by turning shaft 14 into the position shown in FIGURE 5 in which the lobes 13' have pressed the rollers 12' and 17' outwardly through a distance Sufficient to cause the gripper pads 6 and 9 to embrace the end of the blank 5 for centering it relative to the froe 25. The plunger 26 will then be projected to drive the froe into the end of the blank for splitting it into boards. Following this splitting operation the cam will be roated sufficiently to enable the rollers 12 and 17 of the levers 11' and 16 to move toward each other for opening of the levers.

In FIGURES 6, 7 and 8 a different type of apparatus is shown in which the froe 25' is mounted stationarily between the two sides 32 of a "frame while mechanism is provided to drive a blank endwise against the sharpened edge of the froe and past the froe. The side members 32 of the frame are spaced apart a distance sufficient to receive between these frame members on a bed 32 a shake blank of a width as great as would ever be required to be split. As shown in FIGURE 6, such a blank is placed on the bed with its end having the most irregular faces closer to the free 25'.

Between the position of the blank 5 shown in FIGURE 6 and the froe 25' gripping means are located which are shown to be in the form. of rows of resilient fingers 6 and 9 located one above the other. These gripping fingers are supported stationarily by rods 7' and 10', respectively. The gripping fingers are inclined toward each other and toward the fixed froe so that a blank to be split, which is moved endwise toward the froe, m-ust first engage the centering resilient gripper fingers.

From the position shown in FIGURE 6- a blank 5 can be pushed endwise between the rows of gripper fingers and against the :firoe 25' by a ram 33 sliding on the table 32' and moved by plungers 34, which are driven by hydraulic cylinders 35. The ends of these cylinders, remote from the ram 33, are mounted on lugs 36 attached to the frame. Such lugs are connected to the cylinders by pivots 37 to transmit the reaction thrust of the cylinders to the lugs without any tendency of the plungers 34 either to support the weight of the ram 33, or to press the ram down against the bed 32. The ram can merely slide on the surface of the bed.

In order to split a shake blank by the use of this apparatus such blank is laid on the bed 32' between the ram 33 and the rod 7 supporting the upper resilient finger rods 6. When the ram is driven to the left by the cylinders 35 projecting the piston rods 34, the leading end of the blank will be moved between the upper and lower rows of resilient centering gripper fingers 6 and 9 so that the leading end of the blank will be centered with respect to the stationary froe 25'. Continued movement of the ram to the left, as seen in FIGURE 8, will cause the shake blank to be forced on past the opposite sides of the froe to split the blank into upper and lower boards 5a and 5b. The gripper fingers 6 and 9 will continue to press against the opposite sides, respectively, of the blank end boards until such boards have been driven completely past the fingers 6 and 9 and the froe 25. The end of the ram remote from the piston rods 34 has in it a deep groove 33' forming bifurcations which will pass along opposite sides of the froe 25' so that the froe is received in such groove. This ram construction enables the ram to move the boards, into which the blank is split, completely past the froe 25.

The boards 50 and 5b, into which the blank 5 is split, can be deposited on a removal belt conveyor 38 carried at one end by a roller 39. Such belt can transport the boards to a resawing station where the boards can be resawn into individual shakes, as described previously. By the time the boards have been pushed past the froe 25 by the ram 33, the boards 5a and 5b will have passed beyond the position in which the fingers 6 and 9 can engage the boards. Such fingers will have become engaged with the upper and lower sides of the ram 33. Such ram will be moved by the plunger rods 34 into a position such that the stationary froe 25' will be received in the deep groove 33 in the leading edge of the ram 33.

The supply of liquid under pressure to the cylinders 37 is then reversed so that the cylinders will retract the plunger rods 34. Such movement of the plunger rods will withdraw the ram 33 from the position between the resilient gripper fingers 6 and 9 so that these fingers can move into the broken-line positions indicated in FIGURE 8. Retraction of the ram 33 can then be continued until it has been moved into the position shown in FIGURE 6 in which another blank can be deposited on the bed 32 to be split in accordance with the procedure described above.

In the apparatus shown in FIGURES 9 and 10 the blanks 5 to be split can be stacked to be processed successively by the splitting apparatus. In this instance, as in the case of the apparatus shown in FIGURES 6 and 8, the centering grippers are formed of resilient wire fingers 6 and 9 arranged in rows one above the other adjacent to the sharpened edge of the froe 25. In this instance, however, instead of the individual wires being held in individual bores drilled in mounting rods, the supported ends of the wire fingers are clamped between upper and lower bars 40 by bolts 40. The rods are held in properly spaced relationship by filling material 41, as shown in FIGURE 11, in which the supported ends of the wires are imbedded. Such filling material can be resin, babbitt metal or other hard filling material which, preferably, is settable from a liquid or plastic state.

The stack of blanks 5 are supported upon a bed plate 42 of the apparatus above which the side plates 32 project. The blanks are confined between front and rear walls 43 and 44 projecting upward from the side plates 32. Sufficient clearance must be left between the lower edge of the front wall 43 and the bed plate to pass the thickest blank to be split. On the other hand, the lower edge of the front Wall should be spaced above bed plate 42 a distance less than twice the thickness of the thinnest blank to be split. The lower edge of the rear wall 44 should extend downward to a location relative to a ram 45, movable beneath this wall, so as to leave a space between the wall and the ram less than the thickness of the thinnest blank to be split.

The ram 45 is arranged to slide on the bed 42 between the retracted position shown in FIGURE 9 out of registry with the blank-receiving hopper 43, 44 and the projected position shown in FIGURE 10 extending beneath such hopper and to the left beyond it. Such reciprocation of the ram is eifected by application of reciprocating force to the lug 46 projecting downward through a slot in the bed 42. Two or more of such lugs can be provided, if desired. Each of such lugs is connected by a link 47 to an endless drive chain 48 which is mounted on two sprockets 49 and 50 spaced lengthwise of the direction of movement of the ram 45.

The endless chain 48 is driven in the counterclockwise direction, as seen in FIGURES 9 and 10. As the lower end of link 47 is pulled to the left along the upper stretch of the chain 48, the leading end of the ram 45 Willslide through the slot between the lower edge of the rear wall 44 of the blank hopper and the bed 42, and will push the lowest blank from the bottom of the stack. Such blank Will be pushed to the left as seen in FIGURE 9, into engagement with the centering resilient gripping fingers 6 and 9, so that the leading end of the blank will be centered. with repsect to the free 25' by the time such blank end reaches the froe. Continued movement of the ram 45 will force the blank against and past the 'froe so that it will be split into upper and lower boards a and 5b, which will be deposited on the belt conveyor 38.

During such movement of the ram 45 the stack of blanks 5, from which the lowest blank has been removed, will drop onto the upper side of the ram while the blank now lowest in the stack will be held against movement to the left by engagement of its leading end with the lower portion of the front -wall 43. As the ram is retracted movement of the blanks to the right will be prevented by their engagement with the rear wall 44 of the hopper until the ram has been withdrawn completely from beneath the stock into the position shown in FIGURE 9. Such movement of the ram to the right from the position of FIGURE 10 to that of FIGURE 9 will be effected by the link 47 being pushed by the movement to the right of the lower stretch of chain 48.

As the lower end of link 47 is driven upward around the right sprocket 50 the upper stretch of chain will again move the link 47 to the left so that the ram 45 will eject the next lowest blank from the bottom of the stack in the hopper 43, 44 and drive it against and past the froe 25'. A deep groove 45 is formed in the leading end of the ram 45 to receive the froe 25' between the bifurcations of the ram formed by such groove when the ram is in its position farthest: to the left, as shown in FIGURE 10.

The mechanism of FIGURE 12 is generally similar to that of the apparatus illustrated in FIGURES 9 and 10, except that instead of the ram 45 being reciprocated by a link attached to an endless chain the reciprocation of the ram is effected by a plunger 51 reciprocated by a hydraulic cylinder 52, which plunger is attached to a lug 46 projecting downward from the ram through a slot in the bed 42. Such hydraulic cylinder will be doubleacting and the supply and discharge of hydraulic liquid to it will be controlled to effect successive reciprocating strokes of the ram 45 in the manner described in connection with FIGURES 9 and 10.

I claim:

1. Blanksplitting apparatus comprising two opposed resilient centering gripping means, each resiliently deformable to engage irregularities in the surface of one side of a wood blank to be split, a stationary froe adjacent to said gripper means, and pusher means for effecting movement of such blank into engagement with said stationary froe in a direction lengthwise of the grain of such blank while its opposite sides are respectively engaged by said opposed gripper means for splitting such blank centrally.

2. The blank-splitting apparatus defined in claim 1 in which each gripper means includes a row of resilient fingers supported in cantilever fashion.

3. The blank-splitting apparatus defined in claim 1, in which the pusher means includes a reciprocable plunger and a hydraulic cylinder receiving said plunger.

4. The blank-splitting apparatus defined in claim 1, in which the pusher means includes an endless chain driven in a single direction, a blank-engaging member and means connecting said endless chain and said blankengaging member to effect reciprocation of said blankengaginlg member.

References Cited UNITED STATES PATENTS 1,701,001 2/1929 Hampton 144-193 2,610,664 9/1952 Thompson 146-169 3,273,617 9/ 1966 Lamb 146169 FOREIGN PATENTS 578,067 6/ 1959 Canada.

DONALD R. SCHRAN, Primary Examiner. 

